Proximity talks between Israel and the Palestinians will start no later than mid-May, officials involved in efforts to renew the peace process said on Saturday.

On Thursday, Palestinian President Mahmoud Abbas received an official invitation to the talks from U.S. President Barack Obama. In the message to Abbas, Obama acknowledged that he was unable to extract a commitment from Prime Minister Benjamin Netanyahu to freeze construction in East Jerusalem.

But the American president expressed confidence that Israel would refrain from "significant" actions in the eastern part of the city during negotiations. By "significant," Obama appears to mean projects like the 1,600 housing units in the Ramat Shlomo neighborhood of East Jerusalem that were announced during Vice President Joe Biden's visit last month.

In his message to Abbas, Obama wrote that proximity talks with Israel would encompass all the conflict's core issues including Jerusalem, as was agreed in the Annapolis Joint Declaration in November 2007.

On Sunday, Abbas' aides said that the Palestinian leader may meet Obama soon.

Palestinian negotiator Saeb Erekat said that the Palestinians requested such a meeting and were told by Obama's envoy that the U.S. leader would see Abbas in the near future.

Erekat said Sunday that no date was set.

Another aide, Yasser Abed Rabbo, told Palestinian radio that there is talk about an invitation for Abbas to visit Washington, possibly next month.

European officials who have met in recent days with senior officials at the White House and State Department got the impression that the Obama administration did not expect that the proximity talks would produce any agreement.

The efforts to push the peace process forward are meant to allow the United States to claim some success in its Mideast policy as the region marks one year since Obama's historic address in Cairo.

Officials in Washington say that the talks with the Palestinians will force Netanyahu to reveal his positions beyond those outlined in his speech at Bar-Ilan University last June.

The Americans say that if Netanyahu takes an uncompromising stance in the negotiations, like the one he displays in public, the Labor Party might quit the coalition and pave the way for a new government.

Abbas has yet to respond to Obama's message, but a senior source in Ramallah said Saturday that the Palestinian leader would accept the invitation in the coming days. The source says Abbas does not want to be cast as the party who is refusing to negotiate, though Palestinian leaders harbor few expectations that the talks will yield a breakthrough.

A report in Haaretz on Friday that Netanyahu was willing to recognize a Palestinian state with provisional borders only strengthened suspicions among West Bank leaders that the Israeli prime minister wants an interim agreement, not a final-status deal.

Over the weekend, Abbas announced that he rejected Netanyahu's proposal out of hand. A Palestinian official told Haaretz that for the last few months Israel has consistently refused a PA request to allow it to control a four-kilometer strip of land north of the Dead Sea and a route to the area of the planned city of Rawabi. The route traverses Area C, land in the West Bank that is under Israeli civilian and military control.

Earlier this year, Abbas told the Americans that he would agree to a Palestinian state with provisional borders if the interim agreement bases the the permanent borders on the June 4, 1967 lines and proportional land swaps. This principle has been adopted publicly by Secretary of State Hillary Clinton.

The Palestinians have stressed that their position on a state with provisional borders is well known by the Israeli premier. President Shimon Peres, who first broached the idea a year ago, has abandoned it after Egyptian leader Hosni Mubarak expressed his outright opposition to an interim agreement that does not include an Israeli commitment to withdraw to the '67 lines.

Over the weekend, Abbas raised a number of issues that he would like the U.S. administration to address before he officially replies to the invitation. For example, the Palestinian leader sought clarifications about the meaning of "significant" actions in East Jerusalem.

Another matter dealt with the U.S. demand that the PA rein in anti-Israel incitement. Abbas wanted to know whether Washington also requested that Israel take steps to restrain inflammatory statements about the Palestinians.

Haaretz.com, the online edition of Haaretz Newspaper in Israel, and analysis from Israel and the Middle East. Haaretz.com provides extensive and in-depth coverage of Israel, the Jewish World and the Middle East, including defense, diplomacy, the Arab-Israeli conflict, the peace process, Israeli politics, Jerusalem affairs, international relations, Iran, Iraq, Syria, Lebanon, the Palestinian Authority, the West Bank and the Gaza Strip, the Israeli business world and Jewish life in Israel and the Diaspora.